Retrofit of a reciprocating compressor with a concentric valve and a valve clamp having an inlet port in a top cover of the clamp

ABSTRACT

An assembly to retro-fit a valve head of a compressor that may include a valve head including an exhaust orifice, a concentric two-way valve carried by the valve head, and a valve clamp having an intake port in a top of the valve clamp; the valve clamp being removably coupled to the valve head. The valve clamp may include an annular first wall that defines an intake chamber in fluid connection with the intake port and an annular second wall outside the first wall. The space between the first and second walls may define an exhaust chamber in fluid connection with the exhaust orifice of the valve head. The valve clamp may also include a plunger housing to engage and displace a spring-loaded plunger. The plunger housing may be supported on the valve clamp with a plurality of support arms.

CROSS-REFERENCE TO RELATED APPLICATIONS

None

BACKGROUND OF THE INVENTION

Industrial compressors include three basic types: reciprocating, rotary screw, and rotary centrifugal. A reciprocating compressor is a positive displacement machine wherein a piston travels inside a cylinder wherein the piston intakes compressible fluid into the cylinder on a down stroke and exhausts compressible fluid by compressing the compressible fluid on the upstroke. The intake compressible fluid travels through a valve that prevents intake compressible fluid to escape through the inlet on the up stroke. The exhausted compressible fluid travels through a valve that prevents the exhausted compressible fluid from coming back into the cylinder on the down stroke. Thus, multiple reciprocations of the piston causes a volume of compressible fluid to be exhausted into a fixed volume holding tank thereby increasing the pressure inside the holding tank on every reciprocation. The piston continues its reciprocation until a desired pressure is reached in the holding tank. As the compressible fluid inside the holding tank is exhausted out of the holding tank, the piston is then reciprocated as needed to maintain a desired operating pressure.

Essential components for any reciprocating compressor are the valve that allows compressible fluid to flow into the cylinder on the down stroke and the valve that allows compressible fluid to exhaust out of the cylinder during the upstroke. The valves experience millions of cycles during their operating life and when a valve fails or begins to cease to operate effectively, the efficiency and effectiveness of the compressor significantly deteriorates. FIG. 1 illustrates a very common configuration of a first stage of a reciprocating compressor assembly 200. The assembly comprises a piston cylinder 202 having an inner diameter D₁ coupled to a valve head 204 with a seal 206 there between. The valve head 204 can also be called a cylinder head. Valve head 204 is a divided chamber head having an intake orifice 208 that allows compressible fluid to be drawn into an intake chamber 210. One or Two intake valve assemblies 212 are seated within intake chamber 210 and configured to allow compressible fluid to enter the cylinder 202 during the piston's down stroke. For convenience only one of the two intake valve assemblies is shown. Each valve assembly includes a body 250. The body is cylindrical and can be called a valve clamp or holder. The cylindrical body 250 carries a circular one way intake valve 253. The valve carries one or more valve plates (not shown) which move from an open to a closed position. Each valve assembly 212 is a one way, modular, self-contained valve assembly. Valve head 204 further comprises at least one or two exhaust valve assemblies 214 configured to allow compressible fluid to flow out of cylinder 202 during the piston's up stroke into exhaust chamber 216 and subsequently out exhaust orifice 218. For convenience only one of the valve assemblies 214 is shown. Each valve assembly includes a body 254. The body is cylindrical and can be called a valve clamp or holder. The cylindrical body carries a circular one way exhaust valve 257. The valve carries one or more valve plates (not shown) which move from an open to a closed position. The valve assembly is a modular, one way, self-contained valve assembly. Each body 250, 254 would also include a cap or closure (not shown) opposite its valve. Each intake valve assembly 212 is coupled to the valve head 204 and in fluid connection with the intake chamber 210. Each valve assembly 212 extends through respective openings 210′ and 210″ of chamber 210. The openings lead into the interior of chamber 210. Each intake valve assembly 212 extends into chamber 210. Each exhaust valve assembly 214 is coupled to the valve head 204 and in fluid connection with the exhaust chamber 216. Each valve assembly 214 extends through openings 216′ and 216″ of chamber 216. The openings lead into an interior of chamber 216. Each valve assembly 214 extends into chamber 216. Chamber and openings 210, 210′, 210″ are separate, isolated and sealed off from chamber 216 and openings 216′, 216″. Valve assemblies 212 and 214 are coupled to valve head 204 with threading 220 as shown or can be externally bolted (not shown). Valve head 204 is coupled to piston cylinder 202 from above using a plurality of head fasteners 222 inserted through head apertures 227 and through cylinder apertures 224 in the cylinder flange 226 as illustrated. The valve head 204 carries a quad valve arrangement. The prior art also includes dual one way valve arrangements. In this case there is only one intake 212 and one exhaust 214 valve. The valve head is configured accordingly. As an alternative to the above it is be possible that the head and cylinder is integrated as one piece with no gasket between.

Many of these multiple valve compressors have been in operation and either in part or fully the valves have reached the end of their functional life. Partially functioning valves are difficult to recognize, and can significantly affect the overall compressor performance as well as contribute to subsequent subsystem damage. In addition, many of these cases the individual valves have, over the years, become very difficult to remove individually as the connections become fused, or the fasteners corrode to a point that it is extremely difficult to remove the individual valve that is not operating correctly. Further, if one valve is not functioning correctly, it becomes a decision whether to replace the non-functioning valve or all the other valves at the same time. Either option results in increased maintenance costs because replacing the valve before the end of its functional life is wasteful, but paying for maintenance personnel to return to the pump to replace the valve also involves an increase in maintenance costs. Moreover, as the relative labor to material cost differential has changed, the industry maintenance standard has become to remove the entire valve head and valves and replace it with a new or rebuilt valve head including new valves already installed into the head. This method, while more cost effective than trying to replace one or both valves individually, still generates considerable waste and consumes unnecessary maintenance cost resources.

The vast majority of these compressors have a substantial remaining functional life.

SUMMARY OF THE INVENTION

A method for retrofitting a reciprocating compressor embodies the invention. The method includes selecting for removal from a piston cylinder a first valve head. The first valve head is configured to house at least a one way intake valve assembly in an intake chamber of said head and at least a one way exhaust valve assembly in an exhaust chamber of said head. The intake and exhaust chambers sealed off from each other. The first valve head is removed from the piston cylinder. A second valve head is selected. A bottom of the second valve head is removably coupled to the piston cylinder. A concentric two-way valve is seated within the second valve head. The concentric valve is secured within the second valve head with a valve clamp having a top cover. An intake opening of an intake port tis positioned over an intake portion of said concentric valve. The intake opening is positioned at the top of the second valve head. Positioning the intake port, including its intake opening, includes arranging the top cover having the intake opening over the concentric valve, over the intake portion of the concentric valve, and at the top of the second valve head.

An assembly of a compressor that is retrofitted includes an existing piston cylinder, a valve head including an exhaust orifice removably coupled to the piston cylinder, a concentric two-way valve carried within the valve head, and a valve clamp having an intake port with an intake opening in a top cover of the valve clamp. The valve clamp removably coupled to the valve head to secure the valve within the valve head.

The valve clamp extends into a central hollow of the valve head and contacts and secures the concentric valve within the valve head. The valve clamp includes an annular first wall having an inner face and an outer face, the inner face of annular first wall may define an intake chamber. The valve clamp may also include an annular second wall outside the first wall, wherein the second wall has an inner face and an outer face. The inner face of the second wall and the outer face of the first wall may define an exhaust chamber.

The two-way valve may include a spring-loaded plunger to hold open an intake portion of the two-way valve, and facilitate the unloading of the compressor cylinder by allowing intake compressible fluid to escape during the piston up stroke. The valve clamp may also include a plunger housing. The plunger housing may be supported with a plurality of support arms. The plurality of support arms may divide the intake port into a plurality intake ports wherein the intake port is in fluid connection with the intake chamber of the valve clamp.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings form a part of the specification and are to be read in conjunction therewith, in which like reference numerals are employed to indicate like or similar parts in the various views, and wherein:

FIG. 1 is a perspective view of a prior art embodiment of a quad valve head;

FIG. 2 a is a perspective exploded view of one embodiment of a valve retrofit assembly in accordance with the teachings of the present invention;

FIG. 2 b is a perspective exploded view of the valve retrofit assembly shown in FIG. 2 a except FIG. 2 b includes a filter adaptor not shown in FIG. 2 a; and

FIG. 3 is a cross-section of the embodiment of the valve retrofit assembly of FIG. 2 a taken along the line 3-3.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description of the invention references the accompanying drawing figures that illustrate specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled.

FIG. 2 provides an example of a concentric valve head assembly 10 to retrofit with the existing reciprocating compressor piston cylinder 202 shown in FIG. 1. Concentric valve head assembly 10 includes a valve head 12; a concentric valve 14 housed within valve head 12; and a valve clamp 16 that secures concentric valve 14 within valve head 12. The assembly also includes seals 18 for preventing intake compressible fluid and exhaust compressible fluid from escaping their designated flow paths.

Valve head 12 can also be called cylinder head 12. As shown in FIG. 2, valve head 12 includes a top 20, a bottom 22, a sidewall 24, a top flange 26, an exhaust orifice 28 and a hollow 30. The hollow 30 is delimited in the radial direction by inner surface 34 of side wall 24. Accordingly, sidewall 24 in part defines a substantially hollow valve head 12.

Sidewall 24 has an outer face 32 and an inner face 34 formed by inner surface. The sidewall 24 has an axial length defined by top 20 and bottom 22 of valve head 12. The axial length is measured along the axis of the valve head 12. The axis extends from the top 20 to the bottom 22 and through hollow 30. Further, outer face 32 is an outer surface. The outer face of sidewall 24 may include annular ribs 36 around its circumference and may also include vertical ribs (not shown) spanning substantially from bottom 22 to top 20 and radially distributed around the circumference of outer face 32. The pattern of annular ribs 36 and vertical ribs, if any, may serve in part to increase the stiffness of sidewall 24. They may also provide for heat exchange with ambient air by increasing the exposed surface area of the valve head. Sidewall 24 may, alternatively, have a substantially smooth outer face and substantially uniform thickness (not shown). The exhaust orifice 28 opens and extends through side wall 24.

FIG. 2 further shows top flange 26 of valve head 12 extending around the circumference of top 20 of sidewall 24. Flange 26 may also be called an end wall of head 12. Top flange 26 includes a plurality of continuous head coupling apertures 40 that extend continuously and substantially vertical through top 20 and bottom 22 of sidewall 24. Head coupling apertures 40 may be distributed around the circumference of top flange 26 in a known pattern that matches the pattern of cylinder apertures 224 of existing reciprocating compressor assembly 200 shown in FIG. 1. Concentric valve head assembly 10 may be removably coupled to cylinder 202 of existing compressor assembly 200 with head fasteners 42 that extend through head coupling apertures 40 and into or through cylinder apertures 224. Head fasteners 42 are configured to removably couple valve head 12 to cylinder 202 of FIG. 1. Fasteners 42 and fasteners throughout this disclosure may include bolts, screws, clamps, or any other fastening method now known or hereafter developed to result to removably couple two elements. Another embodiment of the present invention could include valve head 12 being permanently coupled to a cylinder through a permanent coupling method including welds or single casting. In this case the single piece casting would replace a separately cast existing head, cylinder and a mating gasket. The existing head and cylinder to be replaced would have the same type of one way modular valves as discussed herein.

Valve head 12 may be configured and proportioned to be used with existing piston cylinders 202 of varying manufactures and diameters D₁ as shown in FIG. 1. Top flange 26 and the pattern and location of head coupling apertures 40 thereon may be configured to match the pattern of apertures 224 on an existing piston cylinder 202 of various manufacturers now known or hereafter developed. In this manner, a user may select a valve head 12 configured to be used with the piston cylinder 202 of a certain manufacturer having a certain size.

As further shown in FIG. 2, concentric valve 14 is a single modular element that performs dual functions and replaces the necessity of two or multiple one way valves. Concentric valve 14 is divided into at least two operable portions including an intake portion 46 and an exhaust portion 48. One embodiment of concentric valve 14 has a circular shape and includes intake portion 46 including and surrounding the center of concentric valve 14 and exhaust portion 48 occupying the outer ring of concentric valve 14 as best shown in FIG. 3. One embodiment of the present invention may include intake portion 46 and exhaust portion 48 having substantially identical areas for allowing the intake and exhaust flow to be substantially equal.

As shown in FIG. 3, concentric valve 14 includes two circular plates combined in one element. Valve 14 provides valved flow of fluid in at least two substantially opposing directions. A first plate 81 is at a top 98 of valve 14. A second plate 85 is at a bottom 96 of valve 14. The two plates 81 and 85 are circular and can be called circular discs. The construction of concentric valves is known in the art and any such construction now known or hereafter developed may be incorporated into valve head assembly 10 of the present invention. Concentric valve 14 may also include a push rod assembly which includes a spring loaded plunger 50 whose main function is to move fingers 52 down thus holding the intake portion of valve 14 and thus stopping the compression process. Air flows into intake portion 46 and back out without compression. The push valve assembly is also known as a suction valve un-loader. An un-loader supply port 88′ is in fluid connection with plunger 50. The supply port extends completely through rib 88 extending across opening 59′ of port 59. The port 88′ also extends through radially opposite sides of ring 61. A first end of rib 88 terminates at a first side of the of the ring 61 through which port 88′ extends. An opposite second end of rib 88 terminates at a second side of ring 61 radially opposite the first side of the ring. The port 88′ extends through the second side of ring 61. When the supply port 88′ is pressurized the plunger 50 is activated and the fingers 52 are pushed down. The compressor operates off-load. When the supply port 88′ de-pressurized the compressor operates under load.

FIG. 2, further shows valve clamp 16 including a top cover 54 that includes coupling tabs 56. A recessed portion 57 may be present between each tab 56. Each tab 56 may include an aperture 58 therethrough. This configuration ensures that tabs 56 fit in-between head fasteners 42 when fasteners 42 are in an installed position in apertures 40 and the head 12 is coupled to cylinder 202. Each tab may also include lift-off apertures 89. The apertures receive threaded bolts to help valve clamp 16 lift off head 12. Valve clamp 16 includes an intake port 59 having an opening 59′ which opens through a top of valve clamp 16. The intake port 59 has a recessed pocket 59″axially between opening 59′ and a top surface of arms 86. The intake port 59 is in fluid connection with intake portion 48 of valve 14. The intake port 59 and opening 59′ are in a central region of the top cover. The intake opening 59′, recessed pocket 59″ and central region are bounded by a raised ring portion 61 of top cover 54 of valve clamp 16. Intake opening 59′ opens through raised ring portion 61. The intake port 59 may alternatively be called an intake orifice.

Now turning to FIG. 3, valve clamp 16 further includes a first wall 60 extending away from a bottom surface 63 of top cover 54. The first wall is annular. First wall 60 includes an inner face 62 and an outer face 64, the inner face 62 and outer face 64 define a wall thickness in the radial direction. First wall 60 also includes a seal protrusion 66 extending from and formed at a free end of first wall 60, wherein the seal protrusion 66 may have a lesser wall thickness than defined by inner face 62 and outer face 64. Seal protrusion 66 is configured to be received into a groove 68 in top 98 of concentric valve 14. The protrusion 66 and groove are annular. An O-ring seal 18 may be seated on the outer radial face of protrusion 66 to create a seal between first wall 60 and concentric valve 14 as shown.

Also shown in FIG. 3, valve clamp 16 includes an annular second wall 70 radially outward of first wall 60 and extending away from bottom surface 63 of top cover 54. First wall 60 and second wall 70 may be substantially concentric. First wall 60 and second wall 70 may be substantially tubular. Second wall 70 has an inner face 72 and an outer face 74. Second wall 70 may include one or more apertures 76′ through both inner and outer faces 72 and 74. Some of the exhaust may flow out of exhaust portion 48, through second wall 70 by way of the apertures 76′. From the apertures 76′ the fluid flows into a portion of the hollow 30, a gap 92, between the outer face 74 and the inner surface 34 of head 12 and from the gap passage in hollow 30 into and out exhaust orifice 28. The second wall 70 also has an aperture 76″ adjacent and overlapping the exhaust orifice 28. The adjacent and overlapping nature allows some of the exhaust fluid to flow into and out orifice 28 without traversing as much of the hollow 30 as exhaust fluid passing through aperture 76′. As further shown, outer face 64 of first wall and inner face 72 of second wall 70 define a space which may be an exhaust chamber 79 that is in fluid connection with exhaust portion 48 of two-way concentric valve 14. Most of the fluid that enters exhaust chamber 79 traverses the chamber 79 until it reaches aperture 76″. It exits chamber 79 through aperture 76″ and out orifice 28. Notably air that passes through apertures 76′ into gap portion of hollow 30 contacts inner surface 34 of head 24 and is cooled due to heat exchange.

As further shown in FIG. 3, inner face 62 of first wall 60 defines an intake chamber 78. Valve clamp 16 includes a plunger housing 80 that comprises a body 82 and a plunger nest 84 configured to receive plunger 50 as shown. An O-ring 18 radially about a top of the plunger 50 seals the plunger 50 to a wall delimiting. Plunger housing 80 may be supported proximate the center of raised ring 61 of top cover 54 with a plurality of support arms 86. Support arms 86 may be disposed radially outward from plunger housing 80 and rib 88. Rib 88 spans across raised ring 61 and divides inlet opening 59′. The rib 88 increases the rigidity of plunger housing 80, and as stated facilitates the ducting of the pressurized air necessary to activate the plunger 50. As shown in FIG. 2, support arms 86 are in a “cross” orientation and, therefore, divide intake port 59 into four defined inlet ports 90 a-d which form inlet port 59. Inlet port 59 is in fluid connection with intake chamber 78. The chamber 78 is in fluid connection with intake portion 46. The fluid connections place intake portion 46 in fluid connection with the exterior environment or other intake channel. For instance in the shown embodiment the intake port 59 is in fluid connection with a port formed in and extending through a tube 300. The tube 300, at a first end 301, is coupled to the ring 61. The coupling places intake port 59 in fluid connection with the port formed in tube 300. The tube 300 at a second end 302 is coupled to a filter (not shown). The tube orients and fluidly connects a filter to head 12 in a place near where it would be connected to head 204 and inlet 208. The second end 302 has the same connection configuration as the connection configuration around inlet 208. There may be any number of arms 86 disposed in any pattern which define any number of inlet ports 90 as sufficient to provide the necessary intake port area to provide the desired intake fluid flow.

When exhaust portion 48 of valve 14 is open, exhaust chamber 79 is in fluid connection with the piston chamber of cylinder 202 allowing the exhaust to flow into exhaust chamber 79 and through apertures 76′, 76″. From apertures 76′ the exhaust fluid flows into gap portion 92 of hollow 30. From the gap portion 92, the exhaust fluid flows into and out of orifice 28. From the aperture 76″ the exhaust fluid flows into orifice 28. Thus exhaust portion 48 is in fluid connection with exhaust chamber 79; exhaust chamber 79 is in fluid connection apertures 76′, 76″; the aperture 76′, are in fluid connection with gap portion 92, gap portion 92 is in fluid connection with orifice 28. Aperture 76″ is in fluid connection with orifice 28 and also gap portion 92. The first wall 60 isolates the intake port 59, intake chamber 78 and intake portion 46, from the exhaust portion 48, the exhaust chamber 79, the exhaust orifice 28, and the gap portion 92 in a manner to substantially prevent exhaust fluid passing out of the exhaust portion from leaking into the intake chamber and to substantially prevent fluid in the exhaust chamber 79, exhaust orifice 28, gap portion 92, and hollow 30 from leaking into the intake chamber and being drawn into the intake portion 46. The first wall 60 fluidly separates the intake portion 46 from the exhaust portion 48. It separates the exhaust fluid from the intake fluid. It diverts the flow to the exhaust orifice from the intake chamber. Wall 60 is a flow diverter.

Now turning to FIG. 3, assembled valve head assembly 10 of the present invention is illustrated in cross section. As shown, inner face 34 of sidewall 24 is positioned at a radius R₁ from the center of valve head 12 and defines a single axially extending hollow passageway 30 therethrough and outer face 32 is located at a radius R₂ from the center of valve head 12 wherein the difference between R₂ and R₁ substantially defines the thickness of sidewall 24 in the radial direction. The gap portion 92 extends circumferentially around the axis of head 12. This gap portion 92 has at least a portion at an axial height measured from the bottom 22 of the valve head 12 which is the same as the axial height of a least a portion of the orifice 28. Opposing ends of gap portion 92 terminate at orifice 28. Further, inner face 34 of sidewall 24 includes a valve seat 94 that concentric valve 14 bears upon within valve head 12.

As further shown in FIG. 3, a portion of the circular valve plate at the bottom 96 of concentric valve 14 is seated on valve seat 94 and valve clamp 16 is inserted within the hollow passageway 30 defined by inner face 34 of valve head 12 such that second wall 70 of valve clamp 16 bear against top 98 of concentric valve 14. Valve clamp 16, and more particularly second wall 70, contacts and secures valve 14 within valve head 12 against valve seat 94. The second wall primarily serves to clamp and secure the valve 16 in sealing engagement with head 12. The valve 16 is sealed to the head 12 with the aid of O-ring 18 coupled around the perimeter of valve 16 and situated between valve 16 and inner face 34 of head 12. Concentric valve 14 may also be nested against inner face 34 of sidewall 24 by any other means known in the art including the outside of concentric valve being angled upward and outward and being wedged into a portion of inner face 34 similarly configured to receive concentric valve 14.

To secure concentric valve 14 within valve head 12 with valve clamp 16, a plurality of clamp fasteners 100 are inserted through apertures 58 of top cover 54 of valve clamp 16 and into clamp apertures 44 of top flange 26 and operated to removably couple valve clamp 16 to valve head 12. One or more seals or O-rings 18 may be positioned on outside face 74 of second wall 70 of valve clamp 16 just under top cover 54 as shown in FIG. 3. One of the apertures 44′ has a position radially offset from the other apertures 44. The clamp has one aperture 58′ also radially offset to match the radial offset of aperture 44′. Having the radial offset apertures ensures that the clamp 16 is coupled to the head 12 to orient the valve clamp aperture 76″ with orifice 28 in an overlapping alignment.

Valve head assembly 10 of the present invention is used to retro-fit existing piston cylinders 202 of a reciprocating compressor assembly 200 shown in FIG. 1 by replacing a valve head 204 with valve head assembly 10 that incorporates a concentric valve 14. Replacing valve head 204 with valve head assembly 10 results in more efficient operation of the reciprocating compressor and substantially reduces maintenance costs with respect to replacing warn out valves. To affect replacement, a user will first remove the existing valve head 204 from piston cylinder 202. The valves 214 and 212 can be removed with the head. The head is removed by releasing a plurality of fasteners 222 coupling the head 204 to the cylinder 202. Seal 206 is removed and cylinder flange 226 of piston cylinder 202. The flange 226 is cleaned and prepared to receive valve head 12 of valve assembly 10. A replacement seal, sealant, or combination thereof may be placed between valve head 12 and cylinder flange 226 to provide an air-tight seal. The replacement concentric valve head is designed to provide equivalent flow capability as to the existing head which utilizes 2 intake valves and 2 exhausts valves. Although FIG. 1 shows a quad valve, it is within the scope of the invention to replace a dual valve head. In this case the valve head replaced only carries one intake valve 212 and one exhaust valve 214. Valve head 12 is removably coupled to piston cylinder 202. More particularly valve head 12 is placed in sealing engagement with cylinder flange 226 and aligned such that head coupling apertures 40 are aligned with apertures 224 in cylinder flange 226. Head fasteners 42 are inserted into and extended through head coupling apertures 40 and are extended through or received by apertures 224 through flange 226. Fasteners 42 are tightened to securely and removably couple valve head 12 to piston cylinder 202.

Concentric valve 14 is placed into hollow 30 of valve head 12. A portion of the circular plate of the bottom 96 of concentric valve 14 is rested upon valve seat 94 as shown in FIG. 3. Intake port 59 is arranged over concentric valve 14. The intake port is arranged over the intake portion 46 of the concentric valve. The intake port 59 is arranged at the top 20 of the head. The intake opening 59′ is arranged in the same manner as the intake port 59. Arranging the intake opening 59′ as described above includes arranging the intake port opening 59′ in the top cover 54 over the concentric valve, over the intake portion 46, and at the top of the head. Arranging the intake port 59 as described above includes arranging the intake port 59 formed in the valve clamp 16 over the concentric valve 14, over the intake portion 46, and at the top 20 of the head. Valve clamp 16 is inserted into hollow 30 of valve head 12. First wall 60 is arranged to be in sealing engagement with concentric valve 14. The seal protrusion 66 is received into groove 68 at the top 98 of concentric valve 14. The second wall 70 bears on top 98 of concentric valve 14. When seal protrusion 66 is received into groove 68, upon valve clamp 16 being secured to valve head 12, the intake chamber 78 is effectively sealed from the exhaust passageway 79 and second wall 70 bears against and seats concentric valve 14 within valve head 12 as shown in FIG. 3. Valve clamp 16 is removably coupled to valve head 12. More particularly, valve clamp 16 is positioned such that apertures 58 align with clamp apertures 44 on top flange 26. Fasteners 100 are inserted through apertures 58 and are received into clamp apertures 44 to couple valve clamp 16 to valve head 12. The fasteners are tightened to removably secure the clamp 16 to the head. Then, any existing intake pipes, such as 300, may be coupled to ring 61 or ring may be coupled directly to a filter. Exhaust pipes may be coupled to valve head 12 and the reciprocating compressor is ready for operation.

In operation, the piston in piston cylinder 202 is stroked and repeatedly translated upward and downward within piston cylinder 202. On the downs stroke, compressible fluid is drawn in through intake port 59 through opening 59′. Fluid passes form intake 59 into intake chamber 78. In the present valve head assembly 10, the placement of the intake port 59 varies from configurations in the prior art. Typically, as shown in FIG. 1, intake orifice 208 is located on the side of a valve head. However, the present valve head assembly 10 re-positions the intake port 59 at the top of the head. The port 59 has its opening at the top and centrally located in the valve clamp. It is at and in the valve top cover. The opening 59′ and port 59 is over the intake portion 46. The positioning results in benefits over a known configuration of a removable valve head having a two way concentric valve. The known head (side entry head) has both the intake and exhaust orifices/outlets located in the sidewall of the valve head. The details are shown in U.S. Patent Publication No. 2013/0121860.

In the present disclosure, because the intake ports are directly above the intake chamber 78 and intake portion 46 of concentric valve 14, the incoming air does not have to make any turns or be directed toward the intake portion 46 of concentric valve 14. Repositioning the intake ports 90 to the top of the present valve head assembly 10 allows the axial height of the valve head 12 to be reduced as compared to the side entry head. The axial height reduction reduces the amount of material saving on material costs. The reduced height also makes the compressor more compact which may be desirable to a person of skill in the art because in many applications, the compressors are located in tight spaces and the reduced height makes it easier maintain or repair the present valve head assembly 10.

Other benefits measured through operational testing indicates that having the intake ports 90 directly above the intake chamber 78 and valve 14 reduces the temperature of the air flow within the valve clamp 16 by an average of 11.8 degrees Fahrenheit as compared to the side entry head. The temperature was measured at test location 102 just above the intake portion 46 of concentric valve 14. The reduced air temperature may provide for more air to be present in a given volume which may thereby increases the volume of flow for identical piston sizes and piston revolutions per minute. For example, in one embodiment of the present valve head assembly 10, compared to the side entry head design, the flow volume increased from 148.0 inlet cubic feet per minute (“icfm”) to 172.0 icfm. This results in a sixteen percent (16%) increase in the volume of air flowing through the intake over having the intake orifice in the side of the valve head when the pistons are driven at the same piston velocity such as rpm.

The temperature and pressure measurements are made during a continually running condition wherein the compressor was driven at a specific speed and allowed to run continually at a specific discharge pressure. The inlet temperature measurement and flow measurement are taken simultaneously. The inlet temperature was measured using a thermocouple and electronic measurement equipment. The flow measurement is done similarly, but by measuring the pressure loss across an orifice at the package discharge. The pressure loss is used in a calculation that allows for other variables including ambient inlet temperature, barometric pressure, and relative humidity. The present valve head assembly 10 performs best when retrofit in single stage compressor or, when compressors with multiple heads and multiple stages are present, the present valve head assembly 10 performs best when retrofit at the low-pressure heads of the first stage. The high-pressure heads perform better when retrofit with the retro-fit the side entry head assembly described in U.S. Patent Publication No. 2013/0121860. Although, it is within the scope of the present invention for the present valve head assembly 10 to be used to retro-fit any compressor head.

Now further describing the operation of the present valve head assembly 10, after air is drawn into the intake chamber 78, intake portion 46 of concentric valve 14 opens to allow intake compressible fluid to be drawn into cylinder 202 as indicated in FIG. 3 by arrow 104. Upon the up-stroke of the piston 228 within cylinder 202, compressible fluid in cylinder 202 is compressed upward. Intake portion 46 of concentric valve 14 closes and exhaust portion 48 of concentric valve 14 opens allowing compressible fluid to be forced out of cylinder 202. The exhaust fluid flows through concentric valve 14 into exhaust chamber 79 between first wall 60 and second wall 70, through apertures 76′, 76″ in second wall 70, and some of the exhaust fluid flows into gap portion 92. The exhaust fluid then flows out exhaust orifice 28 as indicated in FIG. 3 by arrow 106. The piston of the reciprocating compressor 200 cycles repeatedly until one or both of concentric valve portions 46 and/or 48 wears out.

In the event one or both concentric valve portions 46 and/or 48 wear out, a user will remove valve clamp 16 by releasing or removing fasteners 100 and pulling valve clamp 16 upward and out of hollow valve head 12. The user may then remove concentric valve 14 by pulling it upward off of seat 94 and remove it from valve head 12. The user may then insert a new or rebuilt concentric valve 14 such that new or rebuilt concentric valve 14 seats on valve seat 94 and the user may then re-insert valve clamp 16 into hollow 30 of valve head 12 and couple top cover 54 to valve head 12 as described above.

The retro-fit of an existing reciprocating compressor with the valve head assembly 10 of the present invention as described above substantially reduces the time and materials required to maintain the reciprocating compressors and increases the efficiency of the existing compressors by allowing the valve to be immediately proximate the piston of the reciprocating compressor.

From the foregoing it will be seen that this invention is one well adapted to attain all ends and objects hereinabove set forth together with the other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

Since many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative, and not in a limiting sense. 

I claim:
 1. An assembly of a compressor comprising: a piston cylinder; a valve head including an exhaust orifice, said valve head removably coupled to said piston cylinder; a concentric two-way valve carried by said valve head; and a valve clamp, said valve clamp removably coupled to said valve head, said valve clamp extending into a central hollow of said valve head, said valve clamp contacting and securing said concentric valve within said valve head; an intake opening, wherein the opening opens into an intake port, said intake opening is positioned over said concentric valve and forms part of said intake port, said opening formed in said valve clamp.
 2. The assembly of a compressor of claim 1 wherein said valve clamp includes an first wall having an inner face and an outer face, said inner face of said first wall defining an intake chamber, said intake chamber is in fluid connection with said intake opening, intake port and an intake portion of said concentric valve, said intake opening formed in said valve clamp.
 3. The assembly of a compressor of claim 2 wherein said valve clamp includes a second wall radially outward of said first wall, said second wall having an inner face and an outer face, said inner face of said second wall and said outer face of said first wall defining an exhaust chamber.
 4. The method for retrofitting a reciprocating compressor of claim 3 wherein said concentric valve having a first circular plate at a top of said concentric valve and a second circular plate at a bottom of said concentric valve.
 5. The method for retrofitting a reciprocating compressor of claim 1 further comprising aligning a plurality of apertures of said top cover with a plurality of clamp apertures in said second valve head, wherein said apertures in said top cover are in tabs of said top cover and said tabs are defined by recesses between said tabs.
 6. The assembly of a compressor of claim 5 wherein a plurality of support arms divides said intake port into one or more intake ports, wherein said intake ports are in fluid connection with an intake chamber of said valve clamp.
 7. A method for retrofitting a reciprocating compressor comprising: selecting for removal from a piston cylinder a first valve head, said first valve head having been configured to house at least a one way intake valve assembly in an intake chamber of said head and at least a one way exhaust valve assembly in an exhaust chamber of said head, said intake and exhaust chambers sealed off from each other; removing said first valve head from said piston cylinder; selecting a second valve head; removably coupling a bottom of the second valve head to said piston cylinder; seating a concentric two way valve within said second valve head; positioning an intake opening in a top cover of a valve clamp over said concentric valve, wherein said intake opening opens into an intake port in said valve clamp, and said intake opening forms part of said intake port; securing said concentric valve within said second valve head with said valve clamp having said top cover; and removably coupling said top cover to said second valve head.
 8. The method for retrofitting the reciprocating compressor of claim 7 wherein the step of positioning said intake opening over said concentric valve includes arranging said intake opening over an intake portion of said concentric valve.
 9. The method for retrofitting the reciprocating compressor of claim 8 further comprising: forming a fluid connection between the intake opening and intake portion.
 10. The method for retrofitting the reciprocating compressor of claim 9 wherein the step of forming the fluid connection comprises forming a radial outward sealing engagement between a first wall of said valve clamp and said two way concentric valve.
 11. The method for retrofitting the reciprocating compressor of claim 10 wherein the step of forming the fluid connection comprises forming with said first wall an intake chamber in fluid connection with said intake opening and said intake portion.
 12. The method for retrofitting the reciprocating compressor of claim 11 wherein the step of forming the fluid connection comprises forming an exhaust chamber with said first wall, said exhaust chamber in fluid connection with an exhaust portion of said concentric valve.
 13. The method for retrofitting the reciprocating compressor of claim 12 wherein the step of forming the fluid connection comprises isolating the intake chamber and intake portion from the exhaust portion and exhaust chamber to substantially prevent exhaust fluid passing out of the exhaust portion from leaking into the intake chamber and to substantially prevent fluid in the exhaust chamber from leaking into the intake chamber and being drawn into the intake portion. 